[PATCH] mm/compaction: fix the total_isolated in strict mode

[Qiang Liu <liuq131@chinatelecom.cn>]

If the last cycle reads bogus compound_order() and blockpfn > end_pfn occurs,
it is possible that total_isolated will be less than nr_scanned. In this case,
strict mode should return 0, but the “if (strict && blockpfn < end_pfn)”
statement cannot recognize this situation

Signed-off-by: Qiang Liu <liuq131@chinatelecom.cn>
---
 mm/compaction.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index a2b16b08cbbf..6009f5d1021a 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -699,7 +699,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
 	 * pages requested were isolated. If there were any failures, 0 is
 	 * returned and CMA will fail.
 	 */
-	if (strict && blockpfn < end_pfn)
+	if (strict && (blockpfn < end_pfn || total_isolated != nr_scanned))
 		total_isolated = 0;
 
 	cc->total_free_scanned += nr_scanned;
-- 
2.27.0